Distribution and Toxicological Risk Evaluation of Pb, Cd, As and Zn from Surface Soils of Selected Marts in Port Harcourt, Rivers State, Nigeria

It is very pertinent to carry out environmental studies for the assessment of human health risks associated with heavy metal accumulation of frequently visited environments. By Atomic Absorption Spectrophotometry, Lead (Pb), Zinc (Zn), Cadmium (Cd) and, Arsenic (As) were analyzed in top soil samples from Rumuokoro mart (RUM), Choba mart, Mile 3 mart, Mile 1 mart , Town mart (TM), Trans-Amadi mart (TRANS), Boundary mart (BOUND), Oil mill mart (OIL M), Eleme mart (ELE). The concentration of zinc was highest in the mart sites among the other metals. There was pollution with some of the heavy metals at some mart sites. The highest Igeo was found for cadmium at TRANS. The study further established contamination with some of the metals in some of the mart sites as very high contamination with arsenic was observed in RUM. The enrichment factor result obtained revealed that all the metals in all the mart sites occurred as a result of anthropogenic origin except that of lead in MILE 3 that was from natural activities. The levels of average daily intake of all the metals in all the sites were found to be below their respective reference doses. The highest average daily intake of all the metals investigated was observed in zinc at BOUND. No significant health hazard could result from the levels of the metals deposited in the study sites as they did not exceed the reference level at 1.0. RUM is observed as the likely mart site vulnerable to significant health hazards of all sites assessed. Regular environmental assessment should be performed in order monitor and regulate these metals in order to minimize health risks.